Clinical Presentation

A 37-year-old woman presents with hemiplegia.

(A) Chest radiograph shows a well-circumscribed mass in the left lower lobe (arrow). (B) Magnetic resonance image shows a ring-enhancing lesion in the right hemisphere with mass effect. (C) Follow-up computed tomographic angiogram (CTA) shows an arteriovenous (a-v) malformation in the right lower lobe (arrow). Other a-v malformations were present bilaterally. (D) Selected pulmonary arteriogram shows artery (arrow) and vein (arrowhead) of the a-v malformation. (E) Repeat angiogram shows stasis in artery (arrow) supplying angiogram after deployment of an occluding device (arrowhead).

Differential Diagnosis

• Pulmonary arteriovenous malformation: Suggested by vessels associated with a smoothly marginated nodule coupled with a brain lesion suspected to be an abscess resulting from a paradoxical embolus.
  
• Primary lung cancer or metastatic disease: May present as a smoothly marginated nodule with a ring-enhancing brain metastasis.

Essential Facts